Khan Academy provides great lectures on technical material, but very little on humanities and there is no classroom experience at all. To be educational it needs to be combined with other materials and experiences. - crassfool

I'm not disagreeing with you on fundamental grounds, because I, too, believe in the classroom experience and the give and take between teachers and pupils. However, I still remember my Inorganic Chemistry 101 class my freshman year of college which consisted of some 100+ students and a mediocre (at best) professor. The class (at a major state university) was designed to cull students from the science curriculum right from the git go. It did just that. Khan Academy lectures represent a vast improvement on that model.

Education became far more enlightening when I entered graduate studies with small class sizes and dedicated professors. There's no substituting THAT experience with video lectures.